Analysis of heterogeneity of the different health technology assessment reports produced on the transcatheter aortic valve implantation in patients with severe aortic valve stenosis at low surgical risk.

Background: Symptomatic severe aortic stenosis is a congenital or acquired aortic valve disease that occurs when the aortic valve of the heart narrows. It represents the most common valvular disease in adults and generally has a degenerative nature. Transcatheter aortic valve implantation (TAVI), due to its non-invasive approach, has become the standard treatment in patients who are ineligible to surgery or at high surgical risk, and it is also increasingly being performed in patients at intermediate to low surgical risk. The aim is to analyze the heterogeneity and explore the limitations of current health technology assessments (HTAs) on TAVI. Methods: For the purpose of this analysis, a review of the literature based on manual research was performed. A population, intervention, comparators, and outcome (PICO) model was used to gather the HTA reports assessing TAVI in the treatment of patients affected by symptomatic severe aortic valve stenosis at low surgical risk. Furthermore, a manual search has been developed to also include assessments from the Haute Autorité de Santé. Results: At the end of the investigation, a certain degree of heterogeneity in the evidence factored and in the recommendations on the technology has emerged. Relative to the clinical domains, the main drivers for the disparity are found in the type of evidence considered and in the use or not of the grading of recommendations, assessment, development, and evaluation (GRADE) methodology to evaluate the quality of the clinical evidence included. Another element concerns the chosen device generation assessed within the evaluation. In order to perform the economic evaluation, a cost-utility analysis and a budget impact model were developed. Despite some elements of heterogeneity, the economic assessments demonstrate a favorable or dominant cost-effectiveness profile for TAVI compared with surgical aortic valve replacement (SAVR). Conclusion: Despite the presence of heterogeneity elements both in clinical and economic domains, HTA agencies reached the same recommendations on the use of TAVI. It emerged the need for a centralized vision on the "strong" domains, which means giving up freedom to local bodies to adapt to their context on the "soft" ones. This approach could have the potential to strengthen the role of HTA in Europe by ensuring faster decision-making and equity of access to health innovations and reduce the heterogeneity in the assessment methods.